Magnetic conveyor system

ABSTRACT

A magnetic conveyor system is provided for transporting flat elements or plates such as electrophotographic plates or chips which comprise a photoconductive sheet on a conductive backing. This is accomplished by the use of magnetic rollers each of which includes a bar magnet rotatable on a nonmagnetic shaft and having poles at opposite ends thereof to which is attached a pole piece. These pole pieces each have a larger diameter than the magnet to form a groove between the magnet and the pole pieces. This groove is filled with a nonconductive ring or annulus which extends outwardly beyond the edges of the pole pieces to provide a tire or friction bearing surface for the plates or elements to be transported thereby. The plates can be moved from an approach plane to an exit plane by means of a polygonal-shaped roller which is provided at the intersection of the planes and which has alternating flats and ridges so that when an advancing plate engages a polygonal roller and has passed the last round roller in the approach plane it will be rotated with the polygonal roller due to attraction to one of the flats to the exit plane and be fed forwardly by the round rollers in the exit plane. To assure that the plate separates from the last round roller in the approach plane, a stripper bar is provided between the last roller and the polygonal roller which prevents the trailing end of the plate from following the last roller around. Alternatively, the entire roller can be encapsulated in a nonmagnetic material.

United States Patent [451 June 20, 1972 Gnage et al.

[54] MAGNETIC CONVEYOR SYSTEM [72] Inventors: Oliver W. Gnage; Gordon F.Connolly, both of Rochester, NY.

[73] Assignee: Estman Kodak Company, Rochester, N.Y.

[22] Filed: July 6, I970 211 App]. No.: 52,153

[52] US. Cl. ..l98/41, 29/132, l98/33 AD [51] lntJ B65g47/00 [58] FieldofSearch ..l98/4l, 33 R; 271/63 A, DIG. 3; 226/93; 29/125, 132; l00/DlG.17; 193/35 [56] Relerences Cited UNITED STATES PATENTS 3,149,403 9/1964Aurich et al. ..l00/DlG. 17 3,352,397 11/1967 Becker et al ..l93/35 APrimary Examiner-Richard E. Aegerter Assistant Examiner-Douglas D. WattsAuomeyRobert W. Hampton and Gary D. Fields '57 ABSTRACT is attached apole piece. These pole pieces each have a larger diameter than themagnet to form a groove between the magnet and the pole pieces. Thisgroove is filled with a nonconductive ring or annulus which extendsoutwardly beyond the edges of the pole pieces to provide a tire orfriction bearing surface for the plates or elements to be transportedthereby. The plates can be moved from an approach plane to an exit planeby means of a polygonal-shaped roller which is provided at theintersection of the planes and which has alternating flats and ridges sothat when an advancing plate engages a polygonal roller and has passedthe last round roller in the approach plane it will be rotated with thepolygonal roller due to attraction to one of the flats to the exit planeand be fed forwardly by the round rollers in the exit plane. To assurethat the plate separates from the last round roller in the approachplane, a stripper bar is provided between the last roller and thepolygonal roller which prevents the trailing end of the plate fromfollowing the last roller around. Alternatively, the entire roller canbe encapsulated in a nonmagnetic material.

6 Clalns, 6 Drawing Figures PliTiflTEnJuxzolsrz 3,670,868 SHEET1UFTRANSFER I DEVELOPING ouvea w. e GORDON E com INVENTOR BY A. 34% 30ATTORNEYS PATENT'EDJum m2 3.670.868

sum 2 or OLIVER W. GNAGE GORDO CONNELLY VENTORS BY JKJAMA,

fizz/M ATTORNEYS PKTENTEBmzo m2 3,6?0868 SHEET 30F s G 6 OLIVER w. GNAGEw; GORDON F. CONNELLY INVENTORS 9 BY A 21% 50 54 52 63M 0 ATTORNEYSMAGNETIC CONVEYOR SYSTEM CROSS-REFERENCE TO RELATED APPLICATIONS Methodand Apparatus for Making Composite Electrophotographic Prints and filedJuly 1, 1968 in the name of John S. Pollock, now U.S. Pat. No.3,583,807.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to a magnetic conveyor'system and more particularly to magneticrollers for transporting flat plates, such as photoconductive elementsthrough a plurality of electrophotographic stations.

2. Description of the Prior Art In commonly assigned copending U.S.application, Ser. No. 741,359 to John S. Pollock, filed July 1, 1968,now U.S. Pat. No. 3,583,807, a method and device are disclosed formaking electrophotographic multiple color prints wherein photoconductiveelements or chips in separate stacks or sets are charged and exposed toeach of a plurality of color separation images projected from anoriginal. An electrostatic latent thus formed on each of the exposedchips is developed and transferred to a receiver in a predeterminedcycle with respect to the other chips wherein the separate images areplaced thereon in registry to form a composite color print. In eachembodiment, the chips move through charging stations, developingstations, transfer stations, cleaning stations, and finally to a storagestation. In order to provide proper time exposure of the chips andproper registry the chips move through the various stations at differentrates depending upon the particular exposure and the particular station.

From the above description, it can be seen that suitable means areneeded for transporting the photoconductive chips from one station toanother and that such means must be capable of directing the chipsthrough a circuitous path along which the chips must change'directionswhen moving from some of the stations to some of the other stations.

Roller conveyors, including magnetic rollers, are well known fortransporting articles of various types but such conveying devices areoften noisy andmay damage the article being transported or may bedamaged themselves if the environment in which they are used iscorrosive.

SUMMARY OF THE INVENTION In accordance with the present invention, aconveyor system for transporting magnetically attractible flat platesalong a path having an approach plane and an exit plane at an angle tothe approach plane is provided. A first set of magnetic rollers arelocated along the approach plane and a second set of magnetic rollersare located along the exit plane. Between I the two sets of rollers is apolygonal roller which has alternating flats and ridges with one of theflats being engageable with a plate as it leaves the last roller of thefirst set to pivot the plate from the approach plane to the exit planeinto engagement with the first roller of the second set. Each of theserollers includes a bar magnet having opposite poles at the opposite endsthereof and pole pieces attractible to each of the poles. A' ring orannulus of nonmagnetic material is provided in the groove formed by thepole pieces to form a nonmagnetic tire or friction bearing surface forsupporting and transporting the photoconductive chips on either theunderside or top side of the rollers as work functions are performedonthe chips. This nonmagnetic material may extend just slightly beyond thepole pieces so that the chip does not rest directly on the metal polepieces but is still influenced by the magnetic field therebetween.

More particularly, the conveyor system contemplates round rollers onnonmagnetic shafts in the approach and exit planes with a polygonalroller therebetween to change the plane in which the chips move. Also, astripping bar is provided between the last roller of the approach planeand the polygonal roller to separate the trailing end of the chip fromthe last roller so that it does not follow it around. The material alsoreduces noise between the chips and the rollers and reduces corrosion ofthe rollers from developing liquid which may get on the rollers from thechips.

As an alternative, the insulating material can be coated over the entireroller, including the pole pieces to further reduce the change ofcorrosion.

Additional advantages of this invention will become apparent from thedescription which follows, taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic sideelevation of an electrophotographic device having a conveyor systemincluding magnetic rollers, constructed in accordance with thisinvention;

FIG. 2 is an enlarged fragmentary side elevation of a portion of theconveyor system of FIG. 1, showing means for moving a photoconductivechip from an approach plane to an exit plane;

FIG. 3 is a perspective view of a set of rollers constructed inaccordance with this invention;

FIG. 4 is a section through one of the rollers of FIG. 3 taken alonglines 4--4 thereof;

FIG. 5 is a perspective view, similar to FIG. 3, but showing a set ofpolygonal rollers; and

FIG. 6 is a section similar to FIG. 4, but showing an alternativeembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In commonly assigned copendingU.S. application, Ser. No. 741,359 entitled, Method and Apparatus ForMaking Composite Electrophotographic Prints to John S. Pollock, filedJuly 1, 1968, an therefor apparatus is disclosed for makingelectrophotographic color prints from color separation originalswhereinthe originals are exposed for varying lengths of time tocompensate for differences in photoconductive speed to different colorranges and to differences in the original from which the prints are tobe made. In the systems disclosed in that application thephotoconductive elements or chips are fed through an endless cycle.These photoconductive elements are stored in a storage chamber and fedfrom the bottom thereof into a charging station and subsequently to anexposure station, a developing station, a transfer station, a cleaningstation, and back to the upper end of the storage compartment.

Such a system is disclosed schematically in FIG. 1 wherein a pluralityof photoconductive elements or chips 4 are stored in a storagecompartment 2. Chips 4 are received in the storage compartment at theupper end thereof and they are dispensed.

by gravity to the lower end of the storage compartment where they arestacked as described in my commonly assigned copending U.S. application,Ser. No. 52,152, entitled Gravity-Fed Storage Device," filed on evendate herewith. The chips are then fed seriau'm from the bottom of thestorage compartment by a pusher mechanism 6 and advanced by a pluralityof spaced rollers 8, which may be magnetic rollers as hereinafterdisclosed. The photoconductive chips are fed by magnetic rollers 8,mounted on shafts 9 past a charging station 10, such as a coronacharging device and onto a multi-sided roller 12 which changes thedirection of the chip to cause it to be moved down by additional rollers8 to a lower plane. The chip again changes direction due to coming incontact with a further multisurfaced roller 12 so that it begins movingin the reversed direction to its initial direction to an exposurestation 14 where the charged surface is exposed to an image from an Asis readily apparent, to advance the chips along an endless path, it isnecessary to periodically cause the chip to change directions by turningthem from an approach plane. This is accomplished by means ofpolygonalrollers 12. Looking at FIG. 2, it can be seen that a chip 4 isinitially in an approach plane 32 and is transported therealong byrollers 8 to polygonal roller 12 which then rotates the chip as shown indotted lines until it lies in exit plane 34 and is advanced by a roller8 adjacent the exit plane. As a chip moving along approach plane 32comes into engagement with polygonal roller 12 it is alternatinglyengaged by flats 36 and ridges 38 thereon until the trailing end thereofleaves the last roller 8 adjacent the approach plane whereupon the chipis supported by a fiat 36 and rotated with roller 12 until the leadingedge of the chip 4 comes in contact with the first roller adjacent exitplane 34 which advances a chip along that plane. To prevent the trailingend of chip 4 from following the last roller 8 adjacent the approachplane around, a nonconductive means, such as stripping bar 40 isprovided between roller 8 and polygonal roller 12, as shown' whichmaintains the trailing end of chip 4 in approach plane 32 until it canbe swung in a counterclockwise direction, as viewed in FIG. 2 bypolygonal roller 12.

A pair of spaced rollers 8 are illustrated in FIG. 3 as mounted on ashaft 9, as shown which may be coated with nonconductive material 42.The rollers are illustrated as being attached to shaft 9 by means ofnonconductive sleeves 44 connected to the shaft, as by a set screw 46,as shown in FIG. 4. Each roller comprises a bar magnet 48, which in thecase. of roller 8 is cylindrical, one end thereof being the north poleand the other the south pole to which are attached pole pieces 50 and52, respectively. These pole pieces have a diameter slightly greaterthan that of magnet 48 so. as to form a groove 54 therebetween in whichis placed a nonconductive material, such as polyurethane, which is inthe fonn of a ring or annulus 56 extending around the magnet in thegroove 54. Ring 56 conveniently extends beyond the edges of pole pieces50 and 52 to serve as a tire so that a chip supported thereon will notmake metal-to-metal contact between the chip and the edges of thepolepieces to reduce noise. A spacing between the edges of the pole pieceand the edge of the tire 56 of 0.005 inches has been found satisfactory.Thus, the diameter of the pole pieces can be 0.010 inches greater thanthe diameter of the magnet. With this spacing or a greater spacing, thechip is still within the magnetic field of the pole pieces so that it isheld firmly against the roller. Of course, the spacing indicated is byway of example and can be greater or smaller as required includesmagnetic rollers for advancing photoconductive chips through acircuitous path and provides means for moving the chips from an approachplane to an exit plane by means of a polygonal roller. A strippingdevice is provided adjacent the last roller adjacent the approach planefor assuring that the trailing end of the photoconductive chip isseparated for a particular application. The smaller the spacing the polepieces 62 and 64 are attached and form a groove with the magnet in whicha ring or tire 66 of nonmagnetic material is provided. I

An alternative embodiment is shown in FIG. 6 wherein a coating 68completely covers rollers 8, filling groove 54 and extending over theends and sides of pole pieces 50 and 52. This structure may be desirableif the photoconductive chips have corrosive material on them, such asdeveloper.

' From the foregoing, the advantages of this invention are readilyapparent. A conveyor system has been provided which from the roller sothat the polygonal roller can turn the chip into the exit plane. Eachroller is constructed with a bar magnet core to which pole pieces areattached and extend beyond the edges of the magnet to form a groovewhich may be filled with a ring or annulus of nonconductive material toserve as a tire for the photoconductive chips. Thus, the chips can beconveyed on either the top side or underside of the rollers as workfunctions are performed on the chips. in an alternative embodiment thenonconductive material can completely coat the pole pieces to protectthem from any corrosive materials that may come in contact therewith.

The invention has been described in detail with reference to preferredembodiments thereof, but it will be understood that variations andmodifications can be effected within the spirit and scope of theinvention.

We claim:

l. A conveyor system for transporting magnetically attractable flatplates, having leading and trailing ends, along a feed path of a typeincluding an approach plane and an exit plane which is located at anangle with respect to said approach plane, said conveyor systemincluding:

a first generally cylindrical magnetic roller rotatably mounted alongsaid feed path at a location for moving such plates along said approachplane; second generally cylindrical magnetic roller rotatably mountedalong said feed path at a location for moving such plates along saidexit plane;

a polygonal magnetic roller rotatably mounted along said feed path at alocation between said first and second roller, said polygonal magneticroller having altemating flats and ridges, at least one of said flatsbeing engageable with a plate leaving said first roller and rotatable topivot such plate from said approach plane to said exit plane and intoengagement with said second roller. 2. A conveyor system, as claimed inClaim 1, further includmeans, located along said feed path between saidfirst roller and said polygonal roller, for stripping the trailing endof the plate from said first roller.

3. The invention defined in claim 1 wherein each of said rollersincludes:

a bar magnet having opposite poles at first and second opposite endsthereof;

a first pole piece attractable to one of said poles;

a second pole piece attractable to the other of said poles, said firstand second pole pieces having a larger diameter than said magnet so thatsaid magnet and said first and second pole pieces form a peripheralgroove; and

an annulus of non-magnetic material mounted in said peripheral groove,said annulus having a larger diameter than said first and second polepieces so that saidannulus periphery contacts and transports suchplates.

4. A magnetic conveyor device for transporting magnetically attractablearticles along a path, said device comprising:

a bar magnet of polygonal configuration and having op-.

first and second pole pieces forming a peripheral groove;

and an annulus of non-magnetic material in said groove to form a tirefor supporting and transporting said articles.

5. A magnetic conveyor device, as claimed in claim 4 wherein:

said annulus has a diameter greater than said first and second polepieces.

6. A magnetic conveyor device, as claimed in claim 5 wherein thediameter of said ring is at least 0.010 inches greater than the diameterof said pole pieces. 5

1. A conveyor system for transporting magnetically attractable flatplates, having leading and trailing ends, along a feed path of a typeincluding an approach plane and an exit plane which is located at anangle with respecT to said approach plane, said conveyor systemincluding: a first generally cylindrical magnetic roller rotatablymounted along said feed path at a location for moving such plates alongsaid approach plane; a second generally cylindrical magnetic rollerrotatably mounted along said feed path at a location for moving suchplates along said exit plane; a polygonal magnetic roller rotatablymounted along said feed path at a location between said first and secondroller, said polygonal magnetic roller having alternating flats andridges, at least one of said flats being engageable with a plate leavingsaid first roller and rotatable to pivot such plate from said approachplane to said exit plane and into engagement with said second roller. 2.A conveyor system, as claimed in claim 1, further including: means,located along said feed path between said first roller and saidpolygonal roller, for stripping the trailing end of the plate from saidfirst roller.
 3. The invention defined in claim 1 wherein each of saidrollers includes: a bar magnet having opposite poles at first and secondopposite ends thereof; a first pole piece attractable to one of saidpoles; a second pole piece attractable to the other of said poles, saidfirst and second pole pieces having a larger diameter than said magnetso that said magnet and said first and second pole pieces form aperipheral groove; and an annulus of non-magnetic material mounted insaid peripheral groove, said annulus having a larger diameter than saidfirst and second pole pieces so that said annulus periphery contacts andtransports such plates.
 4. A magnetic conveyor device for transportingmagnetically attractable articles along a path, said device comprising:a bar magnet of polygonal configuration and having opposite poles atfirst and second opposite ends thereof; a first pole piece attractableto one of said poles; a second pole piece attractable to the other ofsaid poles, said first and second pole pieces being of polygonalconfiguration corresponding to said bar magnet but having a largerdiameter than said magnet, said magnet and said first and second polepieces forming a peripheral groove; and an annulus of non-magneticmaterial in said groove to form a tire for supporting and transportingsaid articles.
 5. A magnetic conveyor device, as claimed in claim 4wherein: said annulus has a diameter greater than said first and secondpole pieces.
 6. A magnetic conveyor device, as claimed in claim 5wherein the diameter of said ring is at least 0.010 inches greater thanthe diameter of said pole pieces.